A month after state education officials released draft guidelines for a tougher teacher evaluation system, Gov. Cuomo said yesterday the changes aren’t tough enough.

In a letter to Board of Regents Chancellor Merryl Tisch, Cuomo blasted the lack of rigor of the proposed evaluations as well as their slow implementation — arguing that the state needs a better way to judge teachers now.

Cuomo has cited the new evaluations as a solution to the city’s stalled bid to abolish “last in, first out” laws governing teacher layoffs — arguing that better evaluations would successfully remove bad teachers.

He called for more weight to be given to student performance on state tests — allowing them to count for 40 percent of a teacher’s rating as opposed to just 20 percent — and to multiple observations from supervisors throughout the year.

Cuomo also said teachers should earn an overall positive rating only if they score well both on objective measures, like test scores, and on subjective ones, like supervisor observations — rather than being able to eke out a good rating by scoring high in just one area.

“Our goal should be to have the best system of evaluation in the nation, yet our proposed system falls short of other states,” wrote Cuomo. “We must not squander the opportunity to set the right course and make New York a leader in evaluating performance in our education system.”

Almost immediately after the governor’s letter was released, the State Education Department put out a statement from Tisch saying the Regents would support Cuomo’s recommendations in their monthly meeting on Monday.

Revised guidelines that already incorporated suggestions submitted by Cuomo and other stakeholders were posted online yesterday afternoon — although the regs weren’t as firm on the timeline for implementing the evaluations as Cuomo wanted.

General guidelines for the new evaluation system were voted into state law last year and also included as part of the state’s winning application for Race to the Top, a $4 billion federal grant competition.

A state task force came up with last month’s draft guidelines, and the revised rules will need Regents approval before they can be implemented.

But the guidelines also leave a lot of wiggle room by requiring that a host of elements get union agreement.

United Federation of Teachers President Michael Mulgrew would say only that he was looking forward to discussing Cuomo’s recommendations with the Regents.

However, the president of the state teachers union questioned whether the most recent changes to the evaluations conformed with last year’s state law, and called Tisch’s statements on the matter “disturbing.”

Some educators also questioned the widsom of trying to rush in evaluations that will have huge ramifications in determining whether a teacher gets tenure, extra pay or even terminated.

“In terms of accelerating the implementation of the evaluations, that’s a challenge,” said Robert Lowry, deputy director of the state’s Council of School Superintendents. “It should be done well.”

Class action

Gov. Cuomo’s proposals for toughening teacher evaluations:

* Allow student performance on state tests to count for 40% of a teacher’s evaluation, rather than set the limit at 20% for state tests and 20% for local assessments

* Require classroom observations to account for 40% of a teacher’s total evaluation – up from 30% – and allow them to be conducted by third-party (external) judges

* Require a positive rating in both the objective (e.g., state tests) and subjective (e.g., formal observations) measures in order for a teacher to receive an overall positive rating

* Implement the evaluations for all teachers in 2011-12, rather than phasing them in over time